MUFFAKHAM JAH COLLEGE OF ENGINEERING AND
TECHNOLOGY
(Affiliated to Osmania University)
Banjara Hills, Hyderabad, Telangana State
INFORMATION TECHNOLOGY DEPARTMENT
MICROPROCESSORS LAB MANUAL
MICROPROCESSORS LAB
S. No.
CONTENTS
PAGE No.
1
Vision of the Institution
I
2
Mission of the Institution
I
3
Vision of the Department
II
4
Mission of the Department
II
5
PEOs
II
6
POs
III
7
8
9
PSOs
Introduction to 8085 Microprocessor
General Guidelines & Safety instructions
IV
IV
XXVII
PROGRAMS
10
Program 1: 8- bit Subtraction
1
11
Program 2: 8- bit Division
2
12
Program 3: Palindrome
3
13
Program 4: Ascending order
4
14
Program 5: Descending order
6
15
Program 6: 16- bit Addition
8
16
17
Program 7: BCD to binary conversion
Program 8: Binary to BCD conversion
9
10
18
Program 9: Addition of a series of numbers
11
19
Program 10: 8- bit Multiplication
13
20
Program 11: Largest number in a list
14
21
Program 12: Stepper Motor
16
22
Program 13: Traffic Light
17
23
Program 14: LCD
18
24
Program 15: 7 Segment display
19
25
Program 16: Generation of Waveforms
20
26
Program 17: 8279 Interfacing
21
27
Annexure-I: Microprocessors Lab-OU Syllabus
22
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
MICROPROCESSORS LAB
1. VISION OF THE INSTITUTION
To be part of universal human quest for development and progress by contributing
high calibre, ethical and socially responsible engineers who meet the global challenge
of building modern society in harmony with nature.
2. MISSION OF THE INSTITUTION
 To attain excellence in imparting technical education from the undergraduate through
doctorate levels by adopting coherent and judiciously coordinated curricular and cocurricular programs
 To foster partnership with industry and government agencies through collaborative
research and consultancy
 To nurture and strengthen auxiliary soft skills for overall development and improved
employability in a multi-cultural work space
 To develop scientific temper and spirit of enquiry in order to harness the latent
innovative talents
 To develop constructive attitude in students towards the task of nation building and
empower them to become future leaders
 To nourish the entrepreneurial instincts of the students and hone their business
acumen.
 To involve the students and the faculty in solving local community problems through
economical and sustainable solutions.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
I
MICROPROCESSORS LAB
3. VISION OF THE DEPARTMENT
Fostering a bright technological future by enabling the students to function as leaders
in software industry and serve as means of transformation to empower society through
ITeS.
4. MISSION OF THE DEPARTMENT
To create an ambience of academic excellence through state of art infrastructure and
learner-centric pedagogy leading to employability in multi-disciplinary fields.
5. PROGRAM EDUCATIONAL OBJECTIVES
1. The Program Educational Objectives of Information Technology Program are as
follows:
2. Graduates will demonstrate technical competence and leadership in their chosen
fields of employment by identifying, formulating, analyzing and creating efficient IT
solutions.
3. Graduates will communicate effectively as individuals or team members and be
successful in varied working environment.
4. Graduates will demonstrate lifelong learning through continuing education and
professional development.
5. Graduates will be successful in providing viable and sustainable solutions within
societal, professional, environmental and ethical context.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
II
MICROPROCESSORS LAB
6. PROGRAM OUTCOMES
PO1: Engineering knowledge: Apply the knowledge of mathematics, science,
engineering fundamentals, and an engineering specialization to the solution of complex
engineering problems.
PO2: Problem analysis: Identify, formulate, research literature, and analyze complex
engineering problems reaching substantiated conclusions using first principles of
mathematics, natural sciences, and engineering sciences.
PO3: Design/development of solutions: Design solutions for complex engineering
problems and design system components or processes that meet the specified needs with
appropriate consideration for the public health and safety, and the cultural, societal, and
environmental considerations.
PO4: Conduct investigations of complex problems: Use research-based knowledge and
research methods including design of experiments, analysis and interpretation of data,
and synthesis of the information to provide valid conclusions.
PO5: Modern tool usage: Create, select, and apply appropriate techniques, resources,
and modern engineering and IT tools including prediction and modeling to complex
engineering activities with an understanding of the limitations.
PO6: The engineer and society: Apply reasoning informed by the contextual knowledge
to assess societal, health, safety, legal and cultural issues and the consequent
responsibilities relevant to the professional engineering practice.
PO7: Environment and sustainability: Understand the impact of the professional
engineering solutions in societal and environmental contexts, and demonstrate the
knowledge of, and need for sustainable development.
PO8: Ethics: Apply ethical principles and commit to professional ethics and
responsibilities and norms of the engineering practice.
PO9: Individual and team work: Function effectively as an individual, and as a
member or leader in diverse teams, and in multidisciplinary settings.
PO10: Communication: Communicate effectively on complex engineering activities
with the engineering community and with society at large, such as, being able to
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
III
MICROPROCESSORS LAB
comprehend and write effective reports and design documentation, make effective
presentations, and give and receive clear instructions.
PO11: Project management and finance: Demonstrate knowledge and understanding
of the engineering and management principles and apply these to one‟s own work, as a
member and leader in a team, to manage projects and in multidisciplinary environments.
PO 12: Life-long learning: Recognize the need for, and have the preparation and ability
to engage in independent and life-long learning in the broadest context of technological
change.
7. PROGRAM SPECIFIC OUTCOMES
PSO1: Work as Software Engineers for providing solutions to real world problems using
Structured, Object Oriented Programming languages and open source software.
PSO2: Function as Systems Engineer, Software Analyst and Tester for IT and ITeS.
8. INTRODUCTION TO 8085 MICROPROCESSOR
8.1 Introduction
The 8085 microprocessor was made by Intel in mid 1970s. It was binary
compatible with 8080 microprocessor but required less supporting hardware thus leading
to less expensive microprocessor systems. It is a general purpose microprocessor capable
of addressing 64k of memory. The device has 40 pins, require a +5V power supply and
can operate with 3 MHz single phase clock. It has also a separate address space for up to
256 I/O ports. The instruction set is backward compatible with its predecessor 8080 even
though they are not pin-compatible.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
IV
MICROPROCESSORS LAB
8.2 8085 Internal Architecture
The 8085 has a 16 bit address bus which enables it to address 64 KB of memory,
a data bus 8 bit wide and control buses that carry essential signals for various operations.
It also has a built in register array which are usually labelled A(Accumulator), B, C, D, E,
H, and L. Further special-purpose registers are the 16-bit Program Counter (PC), Stack
Pointer (SP), and 8-bit flag register F. The microprocessor has three maskable interrupts
(RST 7.5, RST 6.5 and RST 5.5), one Non-Maskable interrupt (TRAP), and one
externally serviced interrupt (INTR). The RST n.5 interrupts refer to actual pins on the
processor a feature which permitted simple systems to avoid the cost of a separate
interrupt controller chip.
Control Unit
It generates signals within microprocessor to carry out the instruction, which has
been decoded. In reality causes certain connections between blocks of the processor be
opened or closed, so that data goes where it is required, and so that ALU operations
occur.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
V
MICROPROCESSORS LAB
Arithmetic Logic Unit
The ALU performs the actual numerical and logic operation such as „add‟,
„subtract‟, „AND‟, „OR‟, etc. Uses data from memory and from Accumulator to perform
arithmetic and always stores the result of operation in the Accumulator.
Registers
The 8085 microprocessor includes six registers, one accumulator, and one flag
register, as shown in Fig 1. In addition, it has two 16-bit registers: the stack pointer and
the program counter. The 8085 has six general-purpose registers to store 8-bit data;
these are identified as B, C, D, E, H, and L as shown in Fig 1. They can be combined as
register pairs - BC, DE, and HL - to perform some 16-bit operations. The programmer
can use these registers to store or copy data into the registers by using data copy
instructions.
Accumulator
The accumulator is an 8-bit register that is a part of arithmetic/logic unit (ALU).
This register is used to store 8-bit data and to perform arithmetic and logical operations.
The result of an operation is stored in the accumulator. The accumulator is also identified
as register A.
Flag Registers
The ALU includes five flip-flops, which are set or reset after an operation
according to data conditions of the result in the accumulator and other registers. They are
called Zero(Z), Carry (CY), Sign (S), Parity (P), and Auxiliary Carry (AC) flags. The
most commonly used flags are Zero, Carry, and Sign. The microprocessor uses these
flags to test data conditions.
Program Counter (PC)
This 16-bit register deals with sequencing the execution of instructions. This
register is a memory pointer. Memory locations have 16-bit addresses, and that is why
this is a 16-bit register. The microprocessor uses this register to sequence the execution of
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
VI
MICROPROCESSORS LAB
the instructions. The function of the program counter is to point to the memory address
from which the next byte is to be fetched. When a byte (machine code) is being fetched,
the program counter is incremented by one to point to the next memory location.
Stack Pointer (SP)
The stack pointer is also a 16-bit register used as a memory pointer. It points to a
memory location in R/W memory, called the stack. The beginning of the stack is defined
by loading 16-bit address in the stack pointer.
Instruction Register / Decoder
This is a temporary storage for the current instruction of a program. Latest
instruction is sent to here from memory prior to execution. Decoder then takes instruction
and „decodes‟ or interprets the instruction. Decoded instruction is then passed to next
stage.
Memory Address Register (MAR)
It holds addresses received from PC for eg: of next program instruction. MAR
feeds the address bus with address of the location of the program under execution.
Control Generator
It generates signals within microprocessor to carry out the instruction which has
been decoded. In reality it causes certain connections between blocks of the processor to
be opened or closed, so that data goes where it is required, and so that ALU operations
occur.
Register Selector
This block controls the use of the register stack. Just a logic circuit which
switches between different registers in the set will receive instructions from Control Unit.
8085 System Bus
The microprocessor performs four operations primarily.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
VII
MICROPROCESSORS LAB
• Memory Read
• Memory Write
• I/O Read
• I/O Write
All these operations are part of the communication processes between microprocessor
and peripheral devices. The 8085 performs these operations using three sets of
communication lines called buses - the address bus, the data bus and the control bus.
Address Bus
The address bus is a group of 16 lines. The address bus is unidirectional: bits flow
only in one direction – from the 8085 to the peripheral devices. The microprocessor uses
the address bus to perform the first function: identifying a peripheral or memory location.
Each peripheral or memory location is identified by a 16 bit address. The 8085 with its 16
lines is capable of addressing 64 K memory locations.
Data Bus
The data bus is a group of eight lines used for dataflow. They are bidirectional:
data flows in both direction between the 8085 and memory and peripheral devices. The 8
lines enable the microprocessor to manipulate 8-bit data ranging from 00 to FF.
Control Bus
The control bus consists of various single lines that carry synchronization signals.
These are not groups of lines like address of data bus but individual lines that provide a
pulse to indicate an operation. The 8085 generates specific control signal for each
operation it performs. These signals are used to identify a device type which the
processor intends to communicate.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
VIII
MICROPROCESSORS LAB
8.3 8085 Pin Diagram
8085 Pin Description
Properties
ƒ
Single + 5V Supply
ƒ
4 Vectored Interrupts (One is Non Maskable)
ƒ
Serial In/Serial Out Port
ƒ
Decimal, Binary, and Double Precision Arithmetic
ƒ
Direct Addressing Capability to 64K bytes of memory
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
IX
MICROPROCESSORS LAB
A8-A15 (Output 3 states)
Address Bus carries the most significant 8 bits of the memory address or the 8 bits of
the I/0 address; 3 stated during Hold and Halt modes.
AD0 - AD 7 (Input/Output 3state)
Multiplexed Address/Data Bus carries Lower 8 bits of the memory address (or I/O
address) appear on the bus during the first clock cycle of a machine state. It then becomes the
data bus during the second and third clock cycles. 3 stated during Hold and Halt modes.
ALE (Output)
Address Latch Enable occurs during the first clock cycle of a machine state and
enables the address to get latched into the on chip latch of peripherals. The falling edge of
ALE is set to guarantee setup and hold times for the address information. ALE can also be
used to strobe the status information. ALE is never 3 stated.
SO, S1 (Output)
Data Bus Status: Encoded status of the bus cycle
S1
S0
0
0
HALT
0
1
WRITE
1
0
READ
1
1
FETCH
RD (Output 3state)
READ indicates the selected memory or 1/0 device is to be read and that the Data Bus
is available for the data transfer.
WR (Output 3state)
WRITE indicates the data on the Data Bus is to be written into the selected memory
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
X
MICROPROCESSORS LAB
or 1/0 location. Data is set up at the trailing edge of WR. 3 stated during Hold and Halt
modes.
READY (Input)
If Ready is high during a read or write cycle, it indicates that the memory or
peripheral is ready to send or receive data. If Ready is low, the CPU will wait for Ready to
go high before completing the read or write cycle.
HOLD (Input)
HOLD indicates that another Master is requesting the use of the address and data
buses. The CPU, upon receiving the Hold request, will relinquish the use of buses as soon as
the completion of the current machine cycle. Internal processing can continue. The processor
can regain the buses only after the Hold is removed. When the Hold is acknowledged, the
Address, Data, RD, WR, and IO/M lines are 3stated.
HLDA (Output)
HOLD ACKNOWLEDGE indicates that the CPU has received the Hold request and
that it will relinquish the buses in the next clock cycle. HLDA goes low after the Hold
request is removed. The CPU takes the buses one half clock cycle after HLDA goes low.
INTR (Input)
INTERRUPT REQUEST is used as a general purpose interrupt. It is sampled only
using the next to the last clock cycle of the instruction. If it is active, the Program Counter
(PC) will be inhibited from incrementing and an INTA will be issued. During this cycle a
RESTART or CALL instruction can be inserted to jump to the interrupt service routine. The
INTR is enabled and disabled by software. It is disabled by Reset and immediately after an
interrupt is accepted.
INTA (Output)
INTERRUPT ACKNOWLEDGE is used instead of (and has the same timing as) RD
during the Instruction cycle after an INTR is accepted. It can be used to activate the 8259
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XI
MICROPROCESSORS LAB
Interrupt chip or some other interrupt port.
RST 5.5/ RST 6.5/ RST 7.5
RESTART INTERRUPTS have the same timing as I NTR except they cause an
internal RESTART to be automatically inserted.
RST 7.5  Highest Priority
RST 6.5
RST 5.5  Lowest Priority
The priority of these interrupts is ordered as shown above. These interrupts have a higher
priority than the INTR.
TRAP (Input)
Trap interrupt is a non-maskable restart interrupt. It is recognized at the same time as
INTR. It is unaffected by any mask or Interrupt Enable. It has the highest priority of any
interrupt.
RESET IN (Input)
Reset sets the Program Counter to zero and resets the Interrupt Enable and HLDA
flipflops. None of the other flags or registers (except the instruction register) are affected The
CPU is held in the reset condition as long as Reset is applied.
RESET OUT (Output)
It indicates that CPU is been reset. It used as a system RESET. The signal is
synchronized to the processor clock.
X1, X2 (Input)
Crystal or R/C network connections to set the internal clock generator X1 can also be
an external clock input instead of a crystal. The input frequency is divided by 2 to give the
internal operating frequency.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XII
MICROPROCESSORS LAB
CLK (Output)
Clock Output is used as a system clock when a crystal or R/ C network is used as an
input to the CPU. The period of CLK is twice the X1, X2 input period.
IO/M (Output)
IO/M indicates whether the Read/Write is to memory or l/O. It is tristated during
Hold and Halt modes.
SID (Input)
Serial input data line:The data on this line is loaded into accumulator bit 7 whenever a
RIM instruction is executed.
SOD (output)
Serial output data line: The output SOD is set or reset as specified by the SIM
instruction.
Vcc
+5V supply.
Vss
Ground Reference
8.4 8085 Addressing modes
They are mainly classified into four:

Immediate addressing.

Register addressing.

Direct addressing.

Indirect addressing.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XIII
MICROPROCESSORS LAB
Immediate addressing
Data is present in the instruction. Load the immediate data to the destination provided.
Example: MVI R, data
Register addressing
Data is provided through the registers.
Example: MOV Rd, Rs
Direct addressing
It is used to accept data from outside devices to store in the accumulator or send the data
stored in the accumulator to the outside device. Accept the data from the port 00H and store
them into the accumulator or Send the data from the accumulator to the port 01H.
Example: IN 00H or OUT 01H
Indirect Addressing
In this mode the Effective Address is calculated by the processor and the contents of the
address (and the one following) are used to form a second address. The second address is
where the data is stored. Note that this requires several memory accesses; two accesses to
retrieve the 16-bit address and a further access (or accesses) to retrieve the data which is to
be loaded into the register.
8.5. 8085 Microprocessor Trainer Kit
8.5.1 Introduction
From the 4 bit microprocessor brought out by Intel in 1971,advancement in
technology have been made and now 8 bit ,16 bit , 32 bit and 64 bit microprocessors are
available and 64 bit and 32 bit microprocessors are dominating the market. From the age of
vacuum tubes and transistors, we are now in the age of microprocessors. Due to its
adoptability and intelligence, they are used extensively. The trainer kit is a low cost 8085
based training tool developed specifically for learning the operation of today's
microprocessor based systems.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XIV
MICROPROCESSORS LAB
8.5.2 Specifications of MPS 85-3:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XV
MICROPROCESSORS LAB
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XVI
MICROPROCESSORS LAB
8.6. 8085 Instruction Set Summary
Mnemonic
Description
Clock Cycles
MOV r1 r2
Move register to register
4
MOV M r
Move register to memory
7
MOV r M
Move memory to register
7
MVI r
Move immediate register
7
MVI M
Move immediate memory
10
LXI B
Load immediate register Pair B & C
10
LXI D
Load immediate register Pair D & E
10
LXI H
Load immediate register Pair H & L
10
LXI SP
Load immediate stack pointer
10
STAX B
Store A indirect
7
STAX D
Store A indirect
7
LDAX B
Load A indirect
7
LDAX D
Load A indirect
7
STA
Store A direct
13
LDA
Load A direct
13
SHLD
Store H & L direct
16
LHLD
Load H & L direct
16
XCHG
Exchange D & E H & L registers
4
PUSH B
Push register Pair B & C on stack
12
PUSH D
Push register Pair D & E on stack
12
PUSH H
Push register Pair H & L on stack
12
PUSH PSW
Push A and Flags on stack
12
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XVII
MICROPROCESSORS LAB
POP B
Pop register Pair B & C off stack
10
POP D
Pop register Pair D & E off stack
10
POP H
Pop register Pair H & L off stack
10
POP PSW
Pop A and Flags off stack
10
XTHL
Exchange top of stack H & L
16
SPHL
H & L to stack pointer
6
JUMP
JMP
Jump unconditional
10
JC
Jump on carry
7/10
JNC
Jump on no carry
7/10
JZ
Jump on zero
7/10
JNZ
Jump on no zero
7/10
JP
Jump on positive
7/10
JM
Jump on minus
7/10
JPE
Jump on parity even
7/10
JPO
Jump on parity odd
7/10
PCHL
H & L to program counter
6
CALL
Call unconditional
18
CC
Call on carry
9/18
CNC
Call on no carry
9/18
CZ
Call on zero
9/18
CNZ
Call on no zero
9/18
CP
Call on positive
9/18
CALL
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XVIII
MICROPROCESSORS LAB
CM
Call on minus
9/18
CPE
Call on parity even
9/18
CPO
Call on parity odd
9/18
RET
Return
RC
Return on carry
6/12
RNC
Return on no carry
6/12
RZ
Return on zero
6/12
RNZ
Return on no zero
6/12
RP
Return on positive
6/12
RM
Return on minus
6/12
RPE
Return on parity even
6/12
RPO
Return on parity odd
6/12
RST
Restart
12
IN
Input
10
OUT
Output
10
INR r
Increment register
4
DCR r
Decrement register
4
INR M
Increment memory
10
DCR
M
Decrement memory
10
INX B
Increment B & C registers
6
INX D
Increment D & E registers
6
INX H
Increment H & L registers
6
NX SP
Increment stack pointer
6
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
10
XIX
MICROPROCESSORS LAB
DCX B
Decrement B & C
6
DCX D
Decrement D & E
6
DCX H
Decrement H & L
6
DCX
SP
Decrement stack pointer
6
ADD r
Add register to A
4
ADC r
Add register to A with carry
4
ADD
M
Add memory to A
7
ADC
M
Add memory to A with carry
7
ADI
Add immediate to A
7
ACI
Add immediate to A with carry
7
DAD B
Add B & C to H & L
10
DAD D
Add D & E to H & L
10
DAD H
Add H & L to H & L
10
DAD
SP
Add stack pointer to H & L
10
SUB r
Subtract register from A
4
SBB r
Subtract register from A with borrow
4
SUB
M
Subtract memory from A
7
SBB M
Subtract memory from A with borrow
7
SUI
Subtract immediate from A
7
SBI
Subtract immediate from A with borrow
7
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XX
MICROPROCESSORS LAB
ANA r
And register with A
4
XRA r
Exclusive Or register with A
4
ORA r
Or register with A
4
CMP r
Compare register with A
4
ANA
M
And memory with A
7
XRA
M
Exclusive Or Memory with A
7
ORA
M
Or memory with A
7
CMP
M
Compare memory with A
7
ANI
And immediate with A
7
XRI
Exclusive Or immediate with A
7
ORI
Or immediate with A
7
CPI
Compare immediate with A
7
RLC
Rotate A left
4
RRC
Rotate A right
4
RAL
Rotate A left through carry
4
RAR
Rotate A right through carry
4
CMA
Complement A
4
STC
Set carry
4
CMC
Complement carry
4
DAA
Decimal adjust A
4
EI
Enable Interrupts
4
DI
Disable Interrupts
4
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XXI
MICROPROCESSORS LAB
NOP
No-operation
4
HLT
Halt (Power down)
5
RIM
Read Interrupt Mask
4
SIM
Set Interrupt Mask
4
8.7. Procedure to Enter & Execute a Program
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XXII
MICROPROCESSORS LAB
8.8. A Sample Program
Aim: To multiply two 8 bit numbers.
Program Analysis: Two 8 bit numbers are stored in memory locations 8100 and 8101.
They are multiplied and the results are stored in memory locations 8200 and 8201.
Program:
Memory
Machine
Label
Opcode
Operand
address
code
8000
AF
XRA A
Clear A
8001
A8
XRA B
Clear B
8002
A9
XRA C
Clear C
8003
21
LXI H
8004
00
8005
81
8006
46
MOV B, M
Move [M] to B
8007
23
INX H
Increment HL pair
8008
86
ADD M
Add [A] to [M]
8009
D2
800A
0D
800B
80
800C
0C
800D
05
800E
C2
800F
08
8010
80
8011
32
8012
00
8100
Comments
Set HL pair as an index
to source memory
L2
JNC
L1
Jump if no carry to L1
L1
INR C
Increment [C]
DCR B
Decrement [B]
JNZ
L2
Jump if nonzero to L2
STA
8200
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
Store [A] in 8200
XXIII
MICROPROCESSORS LAB
8013
82
8014
79
MOV A, C
8015
32
STA
8016
01
8017
82
8018
76
Move [C] to A
8201
Store [A] in memory
location 8201
HLT
Stop program
Result: The program is executed and the results are stored in the memory locations
8200 and 8201.
Input: At 8100 : 03
At 8101 : 02
Output: At 8200 : 06
At 8201 : 00
8.9. 8085 Instructions & Mnemonic Codes
Hex
mnemonic
Hex
mnemonic
Hex
mnemonic
Hex
mnemonic
CE
ACI
8-Bit
3F
CMC
2B
DCX
01
LXI B,16-Bit
8F
ADC
A
BF
CMP A
3B
DCX
11
LXI D,16-Bit
88
ADC
B
B8
CMP B
F3
DI
21
LXI H,16-Bit
89
ADC
C
B9
CMP C
FB
EI
31
LXI SP,16-Bit
8A
ADC
D
BA
CMP D
76
HLT
7F
MOV A A
8B
ADC
E
BB
CMP E
DB
IN
8-Bit
78
MOV A B
8C
ADC
H
BC
CMP H
3C
INR
A
79
MOV A C
8D
ADC
L
BD
CMP
04
INR
B
7A
MOV A D
8E
ADC M
BE
CMP M
0C
INR
C
7B
MOV A E
87
ADD A
D4
CNC 16-Bit
14
INR
D
7C
MOV A H
80
ADD B
C4
CNZ 16-Bit
1C
INR
E
7D
MOV A L
H
SP
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XXIV
MICROPROCESSORS LAB
81
ADD C
F4
CP 16-Bit
24
INR
H
7E
MOV A M
82
ADD D
EC
CPE 16-Bit
2C
INR
L
47
MOV B A
83
ADD E
FE
CPI
34
INR
M
40
MOV B B
84
ADD H
E4
CPO 16-Bit
03
INX
B
41
MOV B C
85
ADD L
CC
CZ 16-Bit
13
INX
D
42
MOV B D
86
ADD M
27
DAA
23
INX
H
43
MOV B E
C6
ADI
09
DAD B
33
INX
SP
44
MOV B H
A7
ANA A
19
DAD D
DA
JC
16-Bit
45
MOV B L
A0
ANA B
29
DAD H
FA
JM
16-Bit
46
MOV B M
A1
ANA C
39
DAD SP
C3
JMP
16-Bit
4F
MOV C A
A2
ANA D
3D
DCR
D2
JNC
16-Bit
48
MOV C B
A3
ANA E
05
DCR
B
C2
JNC
16-Bit
49
MOV C C
A4
ANA H
0D
DCR
C
F2
JP
16-Bit
4A
MOV C D
A5
ANA L
15
DCR
D
EA
JPE
16-Bit
4B
MOV C E
A6
ANA M
1D
DCR
E
E2
JPO
16-Bit
4C
MOV C H
E6
ANA 8-Bit
25
DCR
H
CA
JZ
16-Bit
4D
MOV C L
CD
CALL 16-Bit
2D
DCR
L
3A
LDA
16-Bit
4E
MOV
CM
DC
CC
16-Bit
35
DCR
M
0A
LDAX B
57
MOV
DA
FC
CM
16-Bit
0B
DCX
B
1A
LDAX D
50
MOV
DB
2F
CMA
1B
DCX
2A
LHLD 16-Bit
51
MOV
DC
8-Bit
8-Bit
A
D
Hex
mnemonic
Hex
mnemonic
Hex
mnemonic
Hex
mnemonic
52
MOV D D
71
MOV M C
E5
PUSH H
9E
SBB
53
MOV D E
72
MOV M D
F5
PUSH PSW
DE
SBI
54
MOV D H
73
MOV M E
17
RAL
22
SHLD 16-Bit
55
MOV D L
74
MOV M H
1F
RAR
30
SIM
56
MOV D M
75
MOV M L
D8
RC
F9
SPHL
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
M
8-Bit
XXV
MICROPROCESSORS LAB
5F
MOV E A
3E
MVI
A 8-Bit
C9
RET
32
STA
58
MOV E B
06
MVI
B 8-Bit
20
RIM
02
STAX B
59
MOV E C
OE
MVI
C 8-Bit
07
RLC
12
STAX D
5A
MOV E D
16
MVI
D 8-Bit
F8
RM
37
STC
RNC
97
SUB
16-Bit
5B
MOV E E
1E
MOV E 8-Bit
D0
A
5C
MOV E H
26
MVI
H 8-Bit
C0
RNC
90
SUB
B
5D
MOV E L
2E
MVI
L 8-Bit
F0
RP
91
SUB
C
5E
MOV E M
36
MVI
M 8-Bit
E8
RPE
92
SUB
D
67
MOV H A
00
NOP
E0
RPO
93
SUB
E
60
MOV H B
B7
ORA
A
0F
RRC
94
SUB
H
61
MOV H C
B0
ORA
B
C7
RST 0
95
SUB
L
62
MOV H D
B1
ORA
C
CF
RST 1
96
SUB
M
63
MOV H E
B2
ORA
D
D7
RST 2
D6
SUI
64
MOV H H
B3
ORA
E
DF
RST 3
EB
XCHG
65
MOV H L
B4
ORA
H
E7
RST 4
AF
XRA
A
66
MOV H M
B5
ORA
L
EF
RST 5
A8
XRA
B
6F
MOV L A
B6
ORA
M
F7
RST 6
A9
XRA
C
68
MOV L B
F6 ORI 8-Bit
FF
RST 7
AA
XRA
D
69
MOV L C
D3
OUT 8-Bit
C8
RZ
AB
XRA
E
9F
SBB A
AC
XRA
H
16-Bit
6A
MOV L D
E9
PCHL
6B
MOV L E
C1
POP
B
98
SBB
B
AD
XRA
L
6C
MOV L H
D1
POP
D
99
SBB
C
AE
XRA
M
6D
MOV L L
E1
POP
H
9A
SBB
D
EE
XRI
8-Bit
6E
MOV L M
F1
POP
PSW
9B
SBB
E
E3
XTHL
77
MOV M A
C5
PUSH B
9C
SBB
H
70
MOV M B
D5
PUSH D
9D
SBB
L
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XXVI
MICROPROCESSORS LAB
GENERAL GUIDELINES AND SAFETY INSTRUCTIONS
1. Sign in the log register as soon as you enter the lab and strictly observe your lab timings.
2. Strictly follow the written and verbal instructions given by the teacher / Lab Instructor. If
you do not understand the instructions, the handouts and the procedures, ask the
instructor or teacher.
3. It is mandatory to come to lab in a formal dress and wear your ID cards.
4. Do not wear loose-fitting clothing or jewellery in the lab. Rings and necklaces are usual
excellent conductors of electricity.
5. Mobile phones should be switched off in the lab. Keep bags in the bag rack.
6. Keep the labs clean at all times, no food and drinks allowed inside the lab.
7. Intentional misconduct will lead to expulsion from the lab.
8. Do not insert connectors forcefully into the sockets.
9. NEVER try to experiment with the power from the wall plug.
10. Immediately report dangerous or exceptional conditions to the Lab instructor / teacher:
Equipment that is not working as expected, wires or connectors are broken, the
equipment that smells or “smokes”. If you are not sure what the problem is or what's
going on, switch off the Emergency shutdown.
11. Never use damaged instruments, wires or connectors. Hand over these parts to the Lab
instructor/Teacher.
12. Be sure of location of fire extinguishers and first aid kits in the laboratory.
13. After verification of program output, turn off power supply to the trainer kit. Do not take
any item from the lab without permission.
14. Observation book and lab record should be carried to each lab. Programs of current lab
session are to be written in Observation book and of previous lab session should be
written in Lab record book. Both the books should be corrected by the faculty in each lab.
15. Handling of Microprocessor trainer kit: Sensitive electronic circuits and electronic
components have to be handled with great care. The inappropriate handling of electronic
component can damage or destroy the devices. Therefore, always handle the electronic
devices as indicated by the handout, the specifications in the data sheet or other
documentation.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
XXVII
MICROPROCESSORS LAB
Program 1: 8-BIT SUBTRACTION
Aim: To subtract two 8-bit numbers.
Method: The numbers to be subtracted are stored in memory locations. First number is brought
to accumulator and the second number in the memory is subtracted from it. If a carry is
generated, the result stored in the accumulator is complemented and a 1 is added to it. Finally,
the result and carry are stored in memory locations.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
1
MICROPROCESSORS LAB
Program 2: 8-BIT DIVISION
Aim: To divide two 8-bit numbers.
Method: The numbers to be divided are stored in memory locations. The dividend is moved to
accumulator. The divisor is subtracted from the accumulator content until a carry is generated.
The number of times this subtraction is done will give the quotient and the remaining value in
the accumulator will give the remainder of division.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
2
MICROPROCESSORS LAB
Program 3: CHECKING WHETHER A NUMBER IS PALINDROME
Aim: To check whether the given number is a palindrome or not.
Method: The number to be checked is stored in a memory location. It is fetched to a register and
the first and last nibbles are separated. The first nibble is rotated left and the carry flag is
checked. The last nibble is rotated right and the carry flag is again checked. If the carry flags of
these two operations do not yield the same value, 00 is stored in memory location indicating that
the number is not a palindrome and the program comes to a halt. But if, they yield the same
result the process is repeated 4 times. If it completes 4 iterations successfully ie. the carry flags
for each nibble in an iteration remain the same, 01 is stored in memory location indicating that
the number is a palindrome.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
3
MICROPROCESSORS LAB
Program 4: SORTING NUMBERS IN ASCENDING ORDER
Aim: To sort 10 numbers stored in consecutive memory locations in ascending order.
Method: Initialize cycle counter, comparison counter with corresponding values and the address
pointer to the location where the data is stored. Move the data pointed by the address pointer to
the accumulator. Compare it with next data. If the accumulator content is less than the next data
then exchange the data. Decrement comparison counter. Repeat the process with the next data
until comparison counter is 0. If the comparison counter is zero then decrement cycle counter
and if it is not zero increment the address pointer and repeat the whole process until cycle
counter is zero.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
4
MICROPROCESSORS LAB
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
5
MICROPROCESSORS LAB
Program 5: SORTING NUMBERS IN DESCENDING ORDER
Aim: To sort 10 numbers stored in consecutive memory locations in descending order.
Method: Initialize cycle counter, comparison counter with corresponding values and the address
pointer to the location where the data is stored. Move the data pointed by the address pointer to
the accumulator. Compare it with next data. If the accumulator content is larger than the next
data then exchange the data. Decrement comparison counter. Repeat the process with the next
data until comparison counter is 0. If the comparison counter is zero then decrement cycle
counter and if it is not zero increment the address pointer and repeat the whole process until
cycle counter is zero.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
6
MICROPROCESSORS LAB
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
7
MICROPROCESSORS LAB
Program 6: 16-BIT ADDITION
Aim: To add two 16 bit numbers.
Method: The numbers to be added are stored in two 16 bit registers. They are added and the
resultant sum and carry are stored in memory locations.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
8
MICROPROCESSORS LAB
Program 7: CONVERTING BCD NUMBER TO BINARY
Aim: To convert a BCD number to a binary number.
Method: The number is ANDed with F0 to obtain the first 4 bits. Then it is rotated 4 times left
through carry and the value is stored in a register (say B). The last 4 bits obtained when the BCD
number ANDed with 0F is stored in another register (say C). The value in B is multiplied by 10
and then it is added with the contents of C to obtain the equivalent binary number. The carry, if
any is also stored in some registers.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
9
MICROPROCESSORS LAB
Program 8: CONVERTING BINARY NUMBER TO BCD
Aim: To convert a binary number to BCD number.
Method: The binary number is stored in a register. Count the number of 100s and store it in a
register say A. Count the number of 10s in it and store it in a register say B. Subtract all 100s,
10s from the original binary number and the resulting value is stored in another register. These 3
values stored will give the equivalent BCD number.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
10
MICROPROCESSORS LAB
Program 9: ADDITION OF SERIES OF NUMBERS
Aim: To add ten 8 bit numbers.
Method: Move first data to accumulator. Initialize count register. Add the next data with data in
the accumulator. If there is a carry increments carry register. Decrement the count register. If it is
zero store the result. Else fetch the next data and add with value in the accumulator. Repeat until
carry register is zero.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
11
MICROPROCESSORS LAB
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
12
MICROPROCESSORS LAB
Program 10: 8-BIT MULTIPLICATION
Aim: To multiply two 8 bit numbers.
Method: Store one of the data in a register (say C register). Move the second data to
accumulator. Move the accumulator content to another register (say B register). Set the data in
the C register as a counter. Add the data in B register to the content of accumulator. Decrement
the value in C register. Repeat the addition until the value in the counter register C is zero. The
final value in the accumulator will be the product of the two values.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
13
MICROPROCESSORS LAB
Program 11: LARGEST NUMBER IN A LIST
Aim: To find out the largest of ten 8 bit numbers.
Method: The numbers are stored in consecutive memory locations. The counter register is
initialized with 0A and the address pointer points to the first number. The first number is moved
to a register say B. The address pointer is incremented and counter register is decremented and
the next number is fetched to accumulator. If the content of accumulator is greater than that in B,
it is loaded in B. The counter register is decremented and the process is repeated until the counter
register reaches to 0. The final value in B will give the largest number in the series.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
14
MICROPROCESSORS LAB
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
15
MICROPROCESSORS LAB
Program 12: STEPPER MOTOR
Aim: To rotate stepper motor in forward and reverse direction.
Apparatus required:
Stepper motor, 8085 microprocessor kit, (0-5V) power supply.
Algorithm:
Step 1: Load the ‘HL’ pair wit value from table
Step 2: Move it to ‘B’ register for setting the counter
Step 3: Move the memory value to accumulator and display it by control word
Step 4: Load ‘DE’ register pair with FFFF for starting delay subroutine
Step 5: Run the delay loop control D-register becomes zero.
Step 6: Increment ‘H’ address for next value from table
Step 7: Jump on no zero
Step 8: When B = 0, go to start and restart the program.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
16
MICROPROCESSORS LAB
Program 13: TRAFFIC LIGHT CONTROL
Aim: To control the traffic light system using 8085 and 8255.
Apparatus required:
8085 Microprocessor trainer kit, Traffic light interface board, Regulated Power supply.
Description: The traffic system moves from one state to next state. By changing the delay
between two signals one can change the speed of traffic.
8255 port addresses:
PORT A - 40H
PORT B - 41H
PORT C - 42H
Control word register -43H
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
17
MICROPROCESSORS LAB
Program 14: DISPLAYING TEXT ON LCD
Aim: To display text on LCD using 8085 and 8255.
Apparatus required:
8085 Microprocessor trainer kit, LCD interface board, Regulated Power supply.
Description: LCD interface is connected over J2 of the trainer. When the trainer kit in
KEYBOARD or SERIAL mode it scans system key codes.
8255 port addresses:
Control word register-43H
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
18
MICROPROCESSORS LAB
Program 15: DISPLAYING TEXT ON 7 SEGMENT
Aim: To display text on seven segment display using 8085 and 8255.
Apparatus required:
8085 Microprocessor trainer kit, seven segment display interface board, Regulated Power
supply.
Description: Seven segment display interface is connected over J2 of the trainer. When the
trainer kit in KEYBOARD or SERIAL mode scrolling and flashing of display can be observed.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
19
MICROPROCESSORS LAB
Program 16: GENERATION OF WAVEFORMS
Aim: To generate different waveforms through DAC using 8085 and 8255.
Apparatus required:
8085 Microprocessor trainer kit, DAC interface board, Regulated Power supply, CRO.
Description: Seven segment display interface is connected over J2 of the trainer. When the
trainer kit in KEYBOARD or SERIAL mode the square, triangular, sawtooth and staircase can
be displayed on CRO.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
20
MICROPROCESSORS LAB
Program 17: INTERFACING OF 8279
Aim: To interface 8279 to 8085 microprocessor.
Apparatus required:
8085 Microprocessor trainer kit, 8279 keyboard/display interface board, Regulated Power
supply.
Description: 8279 keyboard/display interface is connected over J2 of the trainer. When the
trainer kit in KEYBOARD or SERIAL mode the pressed key can be displayed on display unit.
Flowchart:
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
21
MICROPROCESSORS LAB
ANNEXURE-I
UNIVERSITY SYLLABUS
BIT 281
MICROPROCESSORS LABORATORY
Instruction
Duration of University Examination
University Examination
Sessionals
3 Periods Per week
3 Hours
50 Marks
25 Marks
Course Objectives:
1. To become familiar with the architecture and Instruction set of Intel 8085
microprocessor.
2. To provide practical hands on experience with Assembly Language Programming.
3. To familiarize the students with interfacing of various peripheral devices with 8085
microprocessor.
List of Experiments
1. Tutorials on 8085 Programming.
2. Interfacing and programming of 8255. (E.g. traffic light controller).
3. Interfacing and programming of 8254.
4. Interfacing and programming of 8279.
5. A/D and D/A converter interface.
6. Stepper motor interface.
7. Display interface.
Note: Adequate number of programs covering all the instructions of 8085 instruction set
should be done on the 8085 microprocessor trainer kit.
INFORMATION TECHNOLOGY DEPARTMENT, MJCET
22